This contract provides a resource for conducting preclinical pharmacology, pharmacokinetic, and metabolism studies with candidate therapeutic agents selected for development by the Division of Cancer Treatment, NCI. Candidate therapies selected for study under this contract arise from peer-reviewed applications submitted to NCI by academic investigators, pharmaceutical companies, or others. Work carried out under the contract includes: (1) development of analytical methods to quantify the levels of test agents in plasma, urine, and other biological matrices; (2) plasma stability and protein binding studies; (3) pharmacokinetic characterization; (4) quantification and identification of metabolites; and (5) assessment of pharmacodynamic effects. The characterizations obtained from these pharmacokinetic investigations were used in the prioritization and selection of agents for further development; in the design of preclinical efficacy and toxicology studies or in regulatory submissions in support of clinical trials of selected agents.